Machine for applying and cutting strips of laminate

ABSTRACT

The machine comprises a substrate feeder ( 1,3,10,11 ), a laminate feeder ( 14,15,16 ) and application means ( 12,18 ) for applying said laminate to said substrates. It further comprises cutting means ( 17,22,23,24 ) for cutting said laminate ( 13 ) betw successive substrates ( 2 ) during application of said laminate ( 13 ) on said substrates ( 2 ).

The present invention concerns a machine for applying strips of laminateto planar substrates and for cutting said strips once applied.

The present invention also concerns a process for applying strips oflaminate to planar substrates and for cutting said strips once applied.

In the field of banknotes and securities, there has been increasingneeds for security features protecting against counterfeiting. Indeed,in the past years, computers, scanners and copy machines have beenextensively developed and today, it is possible to buy very performingdevices at a reasonable price. Since these devices are more performing,it has been at the same time necessary to develop new and improvedsecurity features for securities, such as banknotes, checks, cards (i.e.credit cards), ID cards, passports etc. which would not allow them to becopied by standard computers or scanners, or even modern color copymachines.

Such security features include special inks, so called optical variableinks, used to print specific patterns on the substrate of the note,optical variable devices in the shape of metallized patches orholograms, or also specific patterns, such as moiré patterns and othersimilar patterns, all of which are very difficult if not impossible copyby actual devices, but, on the other hand, are easy to control visually.

Other security means include combinations of superimposed lines and/orpatterns with colors which are only visible under specific conditions,for example UV light or by transparency. Again, the interest of suchsecurity means is that they may easily be printed or placed on thedocument to be protected and also be controlled by simple devices, evenvisually, but they are impossible to reproduce with actual printers,scanners or copy machines.

Another specific technique involves watermarks in which the papersubstrate is marked with lines or patterns only visible in transparency.A further development of this technique concerns pseudo-watermarksconsisting in the creation of a window in the substrate, especially inpaper-based substrates which are normally not transparent, said windowbeing transparent.

It is however very difficult to create or simulate a transparent windowin a paper-based substrate. Transparent windows, as such, are widelyused in polymer-based substrates for banknotes and securities, in orderto form security elements. These polymer based substrates are usuallycompletely transparent, therefore, to create a transparent window, it isonly necessary to leave the chosen zone free of printing. However, inthe case of paper, a non-transparent substrate as such, a first processhas been developed according to which, it is possible to reduce locallythe thickness of the paper in order to create a transparent window inthe substrate. PCT application WO 99/14433 for example discloses thisprocess and the content of this application is incorporated by referencein the present application. According to this known process, a soakingsolution is applied on at least one surface of the paper in one orseveral predetermined zones, then pressure and heat are applied on thesoaked zone so as to evaporate and increase the density of the paper insaid zone relative to the rest of the paper. Thus, these zones have areduced thickness with respect to the rest of the paper and becometransparent.

This first technique however has the drawback of weakening locally thepaper in the zone comprising the window. In particular, the reducedthickness of the window weakens the substrate. Banknotes using such atechnique thus have a reduced lifetime and must be exchanged, i.e. newbank notes must be printed to replace the older damaged ones.

Another technique implies to cut a hole directly in the paper in orderto create the transparent window. For example, PCT application WO95/10420, the content of which is incorporated by reference in thepresent application, discloses said other technique. It is of coursenecessary to cover the hole cut in the substrate, which is done in thiscase by covering the hole with a strip of transparent material, e.g. afoil or a laminate. This document specifically uses the contrast betweenthe transparency of the window and a diffraction structure used as anadditional security feature and placed inside the window. Modern copymachines and scanners are indeed unable to copy a diffraction structureand also a transparent window.

European patent application No. 02405368.8 “Machine for cutting openingsin a substrate” filed on May 6, 2002 in the name of KBA-GIORI S.A., thecontent of which is incorporated by reference in the presentapplication, discloses a machine for cutting openings, such as windows,in a planar substrate, for example a paper substrate.

In the cases mentioned above, the substrate is weakened, either by itsreduced thickness, or by the absence of material (cut hole), thereforethere is a need to use reinforcing means for such substrates. Onereinforcing means of particular interest is made with a strip oftransparent laminate made of an appropriate material, such as, but notlimited to, Polyester (PET) or Polycarbonate (PC) films. Other materialsknown in the art are of course possible. The strip of material isattached to the substrate by conventional techniques such as gluing orother equivalent methods known in the art. An example of application ofsuch a strip of laminate is disclosed in the European patent applicationNo. 02405782.0 filed on Sep. 10, 2002 in the name of KBA-GIORI S.A., thecontent of which is incorporated by reference in the presentapplication.

A strip of laminate may be used also to add a security element to thesubstrate, in the field of securities, such as a banknotes, checks andother similar products. As indicated in EP application No. 02405782.0cited above, additional security elements could be placed on thesecurities, in particular directly on the zone with a reduced thickness,i.e. the transparent zone. One example of a security feature which isparticularly advantageous to use in the present application is disclosedin Swiss Patent application No. 1661/01 filed on Sep. 7, 2001 in thename of KBA-GIORI S.A., the content of this Swiss Patent applicationbeing incorporated by reference in the present application. The securityfeature for printed matter described in this application comprises afirst drawing printed on one side of said printed matter, said drawingbeing made of a first set of geometrical shapes, and a second drawingprinted on another side of the printed matter in register with a secondset of geometrical shapes corresponding to the first set, but in whichone of said sets comprises offset sectors so that when the recto-versoregister is correct, the security feature forms zones of variabledensity that can be seen only in transparency.

In addition, strips of laminate may be used to protect security elementsplaced on the substrate, in particular when the substrate formssecurities, such as banknotes, checks, ID cards, credit cards and othersimilar objects. Typical security elements are disclosed for example inthe European patent application No. 02405203.7 filed on Mar. 15, 2002 inthe name of KBA-GIORI S.A., the content of which is incorporated byreference in the present application. Other security elements are ofcourse known in the art of securities. Once the security elements havebeen placed on the substrate, either by printing (for example with, butnot limited to, optically variable inks), depositing of specificmaterial (for example, but not limited thereto, with so called opticallyvariable devices), patches and other known elements, the securityelement is covered by a strip of transparent laminate as a protection toavoid its deterioration with time.

It is therefore an aim of the invention to improve the known machinesand methods.

More specifically, it is an aim of the present invention to improve themachines for applying laminate on substrates.

Another aim of the invention is to provide a machine which is able toapply at least a strip of laminate on successive substrates and to cutsaid strip or strips between said substrates once the strip or stripshas been applied.

Accordingly, the present invention is defined by the features theclaims.

The present invention will be better understood by the description ofseveral embodiments with the accompanying drawings in which:

FIG. 1 shows an embodiment of the machine according to the invention.

FIG. 2 shows a detailed view of the cutting system for the laminateaccording to the invention in a first position.

FIG. 3 shows a detailed view of the cutting system for the laminateaccording to the invention in a second position.

FIG. 4 shows a detailed view of the cutting system for the laminateaccording to the invention in a third position.

An example of an embodiment of a machine according to the invention isdescribed in a detailed manner with reference to FIG. 1 which shows theprinciple of functioning of the machine. The machine disclosed is amachine which first cuts an opening in the substrate as will beexplained later in this application.

Accordingly, the processing machine is combined with a feeding unit 1which provides the machine with planar substrates 2, such as sheets ofpaper. The feeding unit has a feeder cooperating with a transportingsection 3, for example a chain gripper system or a suction belt or anyother equivalent system known in the art, which feeds the machine withsuccessive substrates 2, such as sheets of paper, in a continuousmanner. Such a feeding unit is known per se in the art of printingmachines for securities.

The substrates or sheets 2 arriving at the end of the transportingsection 3 cooperating with the feeder are then taken by first and secondtransfer cylinders 4, 5 by appropriate means, for example a swingingtransfer device 6, know per se in the art. The second transfer cylinder5 delivers the successively fed sheets 2 to a counter cylinder 7 whichis used to support the sheets 2 while openings are being cut in thesuccessive substrates 2 by a cutting cylinder 8 supporting cutting tools9. The principle of such a machine for cutting openings in a planarsubstrates, such as sheets of paper, is disclosed and described inEuropean patent application No. 02405368.8 filed on May 6, 2002 in thename of KBA-GIORI S.A. The content of this application is enclosed byreference in the present application for the disclosure of a machine forcutting openings in a planar substrate.

Such a cutting machine disclosed in this European patent application No.02405368.8 comprises at least a cutting tool 9 and a counter cylinder 7supporting the substrate 2 and driving said substrate 2 with grippermeans (not shown) around a first axis of rotation, a cutting cylinder 8supporting the cutting tools 9 having the shape of the opening to becut, said cutting cylinder 8 rotating around a second axis of rotationparallel to the first axis of rotation, said second axis being furthermounted on lateral displacement means to bring said cutting cylinder 8in a cutting position with respect to the counter cylinder 7, andevacuation means (not shown) to evacuate the cut part of said substrate2. All these elements are not shown in a detailed manner in FIG. 1,however, the entire principle and device exposed in this European patentapplication No. 02405368.8 are enclosed by reference in the presentapplication and is applicable to the machine of FIG. 1 for the sake ofcompleteness of the present description.

Once the necessary openings have been cut in the substrate or sheet 2,for example with a machine as disclosed in European patent applicationNo. 02405368.8, the sheet 2 is taken away from counter cylinder 7 bytransfer drum 10 and brought to the part of the machine in which a stripof laminate 13 is applied to the successive sheets 2. This part of themachine is similar to the transporting and application machines thathave been disclosed in PCT applications WO 97/35721, WO 97/35794 and WO97/35795, the content of which is enclosed by reference for the sake ofcompleteness of the present application.

The cut substrate 2 is thus taken over by transfer drum 10, preferablydriven by a speed-controllable and/or position controllable motor andtransferred to a further drum, for example a suction drum 11. Thissuction drum 11 has a dedicated speed-controllable and/or positioncontrollable motor by means of which, the circumferential speed of thedrum 11 can be decreased with respect to the machine speed (for examplethe circumferential speed of the processing cylinder 12) such that thedistance between successive sheets of substrate 2 can be reduced beforethey undergo the process of application of laminate 13 with theprocessing cylinder 12. Thus, the quantity of laminate 13 necessary tocover a given number of sheets 2 can be reduced due to the fact that thedistance between successive sheets 2 is reduced, and less laminate islost between the sheets.

The laminate 13 is carried on a roll 14 and is brought from an unwindingstation comprising said laminate roll 14 and guide rolls 15, 16 to alaminate cutting and feeding station. Preferably, the laminate istransparent or partially transparent polyester film with a thickness ofabout 12 to 15 μm with a glue which is thermoplastic or UV curable orwith two components or activable by other means.

The laminate 13 is transferred from cylinder 17 to cylinder 12 at thecontact point of these cylinders as shown in FIG. 1 and follows thencylinder 12 in order to be applied to the substrate, i.e. successivesheets 2 fed in to the machine.

Once the laminate 13 has been applied against the successive sheets 2 ofsubstrate and has been cut between successive sheets 2, the applicationprocess is continued by successive pressure rolls 18 in order for thelaminate 13 cut into a strip of laminate to be properly applied on thesheet of substrate 2. When the application process is finished, thesuccessive sheets of substrate 2 are taken away for further treatmentover cylinder 19, which is preferably a cooling cylinder.

The laminate feeding and cutting station of the machine is described inmore detail with reference to FIGS. 2 to 4 of the present application.As shown in FIG. 2, the laminate 13 is drawn from roll 14 (see FIG. 1)by suction cylinder 17 which comprises a circumferential surface withholes 20, 20′ and an aspiration segment 21 for drawing the laminate 13with the suction cylinder 17. The aspiration segment 21, known in theart, is fixed with respect to the cylinder 17 and is connected to asource of air under depression. When the holes 20 of the cylinder 17open in the aspiration segment 21 on the inner side of the surface, theyare referenced with the number 20′, the air under depression in theaspiration segment 21 also acts upon the laminate 13 through holes 21′thus allowing the cylinder 17 to draw the laminate 13 in rotation withitself, the laminate being held against the surface of cylinder 17 bythe air under depression.

The cutting system used for cutting the laminate works in a mannersimilar to the one described in European patent application No.02405368.8 filed on May 6, 2002 in the name of KBA-GIORI S.A., thecontent of which has been incorporated by reference in the presentapplication. It comprises a cutting cylinder 22, represented in itscutting position in FIG. 2, that is close to the suction cylinder 17.The cutting cylinder 22 further comprises at least two blades 23, 24forming a cutting tool with, preferably, a soft part 25 placed betweenthe blades 23, 24. According to the principles explained in theincorporated European Patent application No. 02405368.8, in order to cutthe laminate 13, the cutting cylinder 17 is displaced in the directionof cylinder 17 to bring the cutting blades 23, 24 in contact withcounter part 26 in cylinder 17. Said counter part 26 is preferably madeof a hard material (i.e. Polycell) and allows carrying out the cuttingoperation by pressure of the blades 23, 24 of the cutting cylinder 22against the counter part 26 of the suction cylinder 17. The cuttingcylinder 22 is preferably driven by an independent drive 27, for examplea motor, as shown in FIG. 2 to have the possibility of varying itsspeed.

Once the cutting operation has been carried out, that is the blades 23,24 have cut a laminate part by a movement of the cylinder 22 towards thesuction cylinder 17 until the blades 23, 24 have reached the counterpart 26, the cutting cylinder 22 is moved away from cylinder 17 as isrepresented in FIG. 3, through known means, and rotated by drive 27 sothat the cut part of the laminate, which is now between both blades 23,24, can be taken by an evacuation system 28, for example by aspiration.The elastic part 25 placed between blades 23, 24 facilitates theevacuation of the cut part of laminate in the system 28.

To displace the cutting cylinder 22 towards the cylinder 17 and awayfrom said cylinder 17, many equivalent systems can be used, for examplean eccentric mechanism or a lever mechanism.

The laminate 13 transported by the cylinder 17 after the cuttingoperation now comprises a segment of laminate, the leading part of whichhas been transferred on the cylinder 12 according to the processdescribed further in this application and the trailing end 30 of whichlies approximately on counter part 26, where the cutting has been made.Next to said trailing end 30 of the segment of laminate, on the counterpart 26, the leading end 31 of the laminate 13 being fed to the machineis situated, the separation between the trailing end of the segment 30and the leading end 31 of the laminate 13 having been created by thecutting operation described above.

While the suction cylinder 17 continues its rotation drawing thelaminate 13, the counter part 26 arrives in contact with cylinder 12,both cylinders 17 and 12 being coordinated such that the trailing edgeof counter part 26 contacts an aspiration strip 29 of the cylinder 12.Indeed, once the cutting has been carried out, the leading edge ofcounter part 26 is covered by the trailing end 30 of a segment oflaminate, whereas the middle part of counter part 26 is not covered bylaminate anymore since this part of laminate has been cut away by theabove described cutting operation, and the trailing edge of the counterpart 26 is covered by the leading end 31 of laminate 13.

At this contact point, the aspiration segment 21 of the cylinder 17 isended so that the segment of laminate is freed from the cylinder 17, andthus able to be transferred onto cylinder 12 and may follow the cylinder12 for further processing and application to a substrate being takenaway by the aspiration strip 29. The leading end 31 of the laminate 13is at this moment applied against the aspiration strip 29 of thecylinder 12 and is accordingly transferred from cylinder 17 to cylinder12, the same place corresponding to the end of the aspiration segment21, and subsequently follows cylinder 12 by further rotation ofcylinders 17 and 12 therefore continuing the transfer process of thelaminate 13 from cylinder 17 to cylinder 12 and then its application toa substrate 2.

This is shown in FIG. 4 which discloses the situation when the cylinders17 and 12 have been further rotating, therefore further transferring thelaminate 13 from cylinder 17 to cylinder 12 before the laminate 13 iscut to form a segment of laminate.

To describe the further processing of laminate 13 drawn along bycylinder 12, reference is made to FIGS. 1 and 4. The leading end 31 oflaminate 13 is drawn by aspiration strip 29 with cylinder 12 and is thenapplied against a sheet of substrate 2 when they meet near the first oneof rolls 18. The laminate 13 is situated between cylinder 12 andsubstrate 2 and is applied against the substrate 2 by the successiverolls 18, for example heating rolls, which heat the assembly ofsubstrate and laminate, hence for example activating a attachment agent,such as glue, of the laminate in order for the laminate to be properlyattached to the substrate 2 and remain on the substrate 2 once it hasbeen cut by the cutting system described above.

Several techniques can be used to avoid that glue is activated in thewindow cut in the substrate. For example, one may selectively apply glueon the laminate, or selectively activate the glue (by heat, light orother means), or one may selectively apply pressure with rolls 18.

To selectively apply glue on the laminate, one can use a glueapplication system with an application roll 31 as shown schematically inFIG. 1, said system and roll 31 depositing glue onto the segment oflaminate carried by cylinder 12. Since the segment of laminate is inregister with the substrate 2, it is possible selectively apply theapplication roll 31 to deposit the glue only on the part of the segmentof laminate that will be effectively in contact with the substrate andnot on the surface of the segment of laminate that covers the window cutin the substrate 2.

Another way can be to selectively activate the glue deposited on thelaminate 13, for example by exchanging the application roll 31 by anactivation means in front of which the segment of laminate passes.Accordingly, the glue will only be activated where the segment oflaminate will contact the substrate, and the surface of the segment oflaminate covering the window of the substrate 2 will not be activated.

According to another possibility, one can selectively apply pressure andheat with the rolls 18, thereby activating the glue by the combinationof pressure and heat and relieving the pressure applied by rolls 18along the part of the substrate that comprises the cut window. Therelieve of pressure could be done by moving the rolls 18 away from thecylinder 12, or by an opening cut in the surface of the rolls thatcorresponds to the window cut in the substrate 2.

Another option is to use a two components glue with one component beingapplied on the substrate and the other component being applied on thelaminate. The glueing process will then only be activated when bothcomponents are present, therefore this would not be the case where thewindow has been cut in the substrate thus avoid the selective techniquesdescribed above.

To improve the efficiency of the system, it would also be possible tocombine the different possibilities indicated above. In another variant,it could be possible to pre-process the film and to deposit athermoactivable glue selectively on the film and in register with theholes or windows cut in the substrate.

When the laminate application operation has been carried out, thesubstrate 2 with the applied segment of laminate is taken away bycylinder 19, which is preferably a cooling cylinder, and undergoesfurther processing, such as printing, quality control etc.

The embodiments of the invention have been given as examples andvariations are possible within the scope of the present protection. Inparticular, the laminate cutting system could be used in any machine inwhich such laminate is applied to successive sheets of substrate, andnot only in a machine in which a window is cut in the successive sheets,the aim being to be able to cut the laminate between successive sheetson which it has been applied.

1. Machine for applying a strip of laminate to successive planarsubstrates, in particular sheets of paper, said machine comprising:application means for applying said laminate to said substrates; asubstrate feeder for feeding successive substrates to said applicationmeans; a laminate feeder for supplying laminate to said applicationmeans; and cutting means for cutting said laminate between successivesubstrates, said cutting means including a counter cylinder and acutting tool which can be brought into contact with said countercylinder to cut the laminate into successive strips of laminate,characterized in that said application means comprises a processingcylinder in contact with said counter cylinder for transporting andapplying the laminate onto said substrates, said counter cylinder andprocessing cylinder being adapted and coordinated to allow transfer of aleading end of the laminate cut by said cutting tool from said countercylinder to said processing cylinder and to draw along the cut laminatebefore the laminate is again cut by said cutting tool to form a strip oflaminate.
 2. Machine according to claim 1, wherein the cutting meanscomprises a cutting cylinder carrying the cutting tool.
 3. Machineaccording to claim 2, wherein the cutting cylinder comprises at leasttwo blades on its outer circumference forming said cutting tool. 4.Machine according to claim 3, wherein a soft part is placed between saidblades.
 5. Machine according to claim 2, wherein the cutting cylinder isdisplaceable laterally with respect to the counter cylinder.
 6. Machineaccording to claim 2, wherein said cutting cylinder is driven by anindependent drive.
 7. Machine according to claim 2, wherein the countercylinder comprises a counter part suitable for cooperation with saidcutting tool.
 8. Machine according to claim 1, further comprising anevacuation system for evacuating a cut part of said laminate.
 9. Machineaccording to claim 1, wherein said counter cylinder comprises aspirationmeans for holding said laminate against the surface of the suctioncylinder and drawing said laminate along in rotation with the countercylinder.
 10. Machine according to claim 9, wherein said aspirationmeans include an aspiration segment which is fixed with respect to thecounter cylinder and a plurality of holes provided in thecircumferential surface of the counter cylinder and adapted to open insaid aspiration segment.
 11. Machine according to claim 10, wherein saidaspiration segment extends, along the direction of rotation of saidsuction cylinder, from a position located before the position where saidcutting tool is brought in contact with the suction cylinder to aposition corresponding to the contact point between said suctioncylinder and said processing cylinder.
 12. Machine according to claim 1,wherein said processing cylinder further comprises an aspiration stripfor aspirating and transferring the leading end of the cut laminate fromsaid counter cylinder to said processing cylinder and for drawing saidleading end of the cut laminate in rotation with the processingcylinder.
 13. Machine according to claim 1, wherein said substratefeeder comprises a drum with a dedicated speed-controllable and/orposition controllable motor by means of which a circumferential speed ofthe drum can be decreased with respect to the circumferential speed ofthe processing cylinder such that the distance between successivesubstrates can be reduced before application of the laminate.
 14. Aprocess of applying a continuous strip of laminate onto successiveplanar substrates, in particular sheets of paper, and cutting said stripof laminate between two successive substrates, said process comprisingthe steps of: transporting the laminate by means of a first cylinder toa cutting tool; bringing the cutting tool in contact with said firstcylinder to cut the laminate into strips of laminate; and applying thestrips of laminate against the substrates, said process beingcharacterized by transferring a leading end of the cut laminate from thefirst cylinder onto a second cylinder contacting the first cylinderbefore cutting again the laminate to form a strip of laminate which isapplied against the substrate by said second cylinder.